Regioselective Carbon-Carbon Bond Formation Reactions between TCNE or TCNQ and a Quinonoid Ring

摘要

Tetracyanoethylene (TCNE) and 7,7',8,8'-tetracyanoquinodimethane (TCNQ) are strong organic, one-electron acceptors, and as such are much used as precursors to electron-transfer salts and superconducting or magnetic materials. The coordination chemistry of TCNE and TCNQ has been much investigated, and their reactions with organometallic compounds include: 1) insertion into M-H,[3a],[b] M-C,[3c]-[f] or M-OR bonds;[3g] 2) [2+2], [4+2], or [3+2] additions on the ligand; 3) α,β-additions to an acetylide group; 4) cycloadditions; and 5) insertions into an aromatic C-H bond. Although numerous reactions of TCNE and TCNQ with organic compounds have been reported, only insertion reactions into a C-C bond of a spiroanellated bicyclopropyl system or a C-H bond of 4-hydroxycoumarins, cyclic enol ethers, phenols, or a mesoionic thiazolium system have been observed.